Djokovic's exit means there will be a first-time Grand Slam champion in the men's draw.
In an absorbing third round match, 23-time Grand Slam winner Williams rallied to defeat 2017 US Open winner Sloane Stephens 2-6, 6-2, 6-2 in one hour and 43 minutes, while second seed Kenin also faced a tough challenge in a straight sets win over Ons Jabeur of Tunisia.
"James, as everyone knows, is a fantastic player with a lot of quality and a lot of ability to make assists for the strikers," Ancelotti said of his new signing.
Elsewhere, Sao Paulo beat Fluminense 3-1 at home thanks to second-half goals from Brenner, Luciano Rocha and Vitor Bueno. Wellington Silva was on the scoresheet for the visitors.
R&F broke the deadlock while Saba forced Jianye defender Chen Hao into an own goal in the 12th minute.
Patrick Bezerra equalized eight minutes later with a header following Thiago Galhardo's cross.
The first set was dominated by the world No. 13, but Cirstea hung tough in the second and pinched it in the tiebreak. After that, Cirstea never looked back.
The ITTF Women's World Cup features 20 athletes, including the world champion, qualified players from all completed continental events (Africa, Europe and Pan America) and players selected by world rankings from the other continents (Asia and Oceania). For each World Cup event, there will be maximum of two players per association. Enditem
On October 12, Dragan Skocic's men will host Tajikistan in the Iranian capital Tehran.
Old dogs such as Toni Kroos (30/Real Madrid) and Manuel Neuer (34/Bayern Munich) might be an exception as they are pillar upon which he can build on.
SIPG promptly adjusted tactics to catch up in the second half but were still scoreless, only to see Brazilian forward Marcos Vinicius seal the result with a low drive for China Fortune in stoppage time.